[技术]Arizona眼睛模型 [复制链接]

简介 8{^GC(W{]  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 x-k/rZ  
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模型 \A"a>e  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 p+1B6j  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. S^_yiV S  
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光源 xo3)dsX  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 78A4n C  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 iFT3fP'> 5  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 c=mFYsSv  
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视网膜的散射 _$x *CP0(  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 35\0g&  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 2z l  
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脚本 7~g0{W>Zm  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： t)ry)[Dxv  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 -M9 4
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余下的脚本计算与屈光度有关的所有参数。 jP]'gQ!-w  
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分析 g9Ll>d)tE3  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 jV8><5C  
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脚本代码 9dv~WtH>5  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. w|ei*L  
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Dim entity As T_ENTITY 1Sr}2@>  
Dim op As T_OPERATION n*uZ=M_/Q  
Dim mat As T_MODELMATERIAL O2B$c\pw  
Dim A As Double C<)&qx3  
Dim pupilDiam As Double 1+#8} z:  
Dim eID As Long zAIC5fvu  
Dim parID As Long Fx\Re]~n  
Dim count As Integer {,-#;A*yW  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Plv+mb  
Dim tlens As Double, nlens As Double )<&QcO_  
Dim curv As Double, conic As Double u?i1n=Ne  
Dim ok As Long 4]R3*F  
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Sub Main vUA,`  
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    '用户输入对话框 c`Cn9bX  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 .j.=|5nVo4  
        TextBox 220,21,40,21,.TextBox1 'default: 0

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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 4 n(
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        OKButton 40,91,90,21 ];YOP%2   
        CancelButton 190,91,90,21 jTIn@Q  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 wOP}SMn  
        TextBox 220,49,40,21,.TextBox2 'default: 4 5
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    End Dialog l+,rc*-j0  
    Dim dlg As UserDialog b/`'?| C  
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    ok = Dialog (dlg) M`FL&Ac  
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    If ok=0 Then    'cancel button was pressed .nJGxz+X"  
        Print "Execution cancelled." ,#{aAx|]  
        End NgKNT}JDv  
    End If .#}R$}e+  
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    'Assign accommodation and pupil diameter & use defaults if field left empty a6C~!{'nW  
    If dlg.TextBox1 = "" Then t/w>t! q  
        A = 0           'Default accommodation 8?!Vr1x  
    Else P? n`n!qZ  
        A = CDbl(dlg.TextBox1) -q27N^A0  
    End If D]REZuHOI  
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    If dlg.TextBox2 = "" Then ]MyWB<9M  
        pupilDiam = 4   'Default pupil diameter lDzVc`c  
    Else pe8MG(V  
        pupilDiam = CDbl(dlg.TextBox2) z\, w$Ef+  
    End If ]2+(i  
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    Print " " 6IA~bkc}  
    Print "Accommodation = " & A & " Diopters" \}5\^&}_  
    Print "Pupil Diameter = " & pupilDiam & " mm" @NZ?D0"  
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    ' Calculate new parameters with accommodation (Y86q\DQ?|  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness #+$z`C`  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens tfO _b5g  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens SrxX-Hir  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens a[!':-R`s  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens b1+Nm  
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    tlens = 3.767 + 0.04*A                  'Lens thickness rz(DZV  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction #*fB~Os:  
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    'Adjust parameters to account for accommodation 6xwC1V?:0t  
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    '************************************************************************* |jlR],  
    'Aqueous thickness (Position of Lens) 0>vm&W<?)  
    '************************************************************************* $%/Zm*H  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" )  )57OZ  
    GetCustomElement eID, entity -<.>jX  
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    parID = FindFullName( "Geometry.Arizona Eye" ) NGNn_1  
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    ' Delete any shift(s) in z 2HUoT\M  
    count = 0 3=z'Ih`  
    While GetOperationCount(eID)>count vg<_U&N=-r  
        GetOperation eID, count, op <=p"ck@  
        If op.Type="ShiftZ" Then ,MdCeA%`  
            DeleteOperation eID,count 3.soCyxmc  
            count=count-1 0=~Ji_5mB  
        End If mR@iGl
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        count=count+1 U^.$k-|k  
    Wend QJxcH$  
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    'Set new shift in "p<f#s}  
    op.Type = "ShiftZ" {oO!v}]  
    op.val1 = taq C0e< _6p=  
    op.parent = parID ],#9L   
    AddOperation eID, op Da.vyp  
    Print "Set aqueous humor thickness = " & taq-0.55 FG?B:Zl%T  
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    '************************************************************************* h)sc-e
 
    'Radius and conic constant of anterior lens rLp0VKPe  
    '************************************************************************* .iw+#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ?k/Uw'J4u/  
    GetConic eID, entity, curv, conic }pA0mW9  
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    SetConic eID, entity, 1/Rant, CCant _TH'v:C  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant iid
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    '************************************************************************* pDW .Pav  
    'Radius and conic constant of posterior lens Xod#$'M>  
    '************************************************************************* p=p
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) H`kfI"u8  
    GetConic eID, entity, curv, conic S);bcowf_  
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    SetConic eID, entity, 1/Rpost, CCpost 6*CvRb&  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost r"^P>8  
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    '************************************************************************* lBl`R|Gt  
    'Lens thickness (Position of posterior lens surface) I/t2c=f  
    '************************************************************************* GDhg VOW(  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) h%Bp%Y9  
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    ' Delete any z-shift(s) 2wikk]Z  
    count = 0 nD|Bo 9  
    While GetOperationCount(eID)>count %-> X$,Q :  
        GetOperation eID, count, op FK>8(M/  
        If op.Type="ShiftZ" Then o[aRG7C  
            DeleteOperation eID,count S9-FKjU  
            count=count-1 8KN0z<  
        End If kowBB0  
        count=count+1 _A1r6  
    Wend bDRl}^aO6  
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    'Set new z-shift W A-\2  
    op.Type = "ShiftZ" rMUn ~  
    op.val1 = tlens iU5M_M$G  
    op.parent = parID (6!W8x7  
    AddOperation eID, op B/AS|i] sM  
    Print "Set lens thickness = " & tlens `|+!H.3  
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    '************************************************************************* VI/77  
    'Lens index of refraction )$XcO]  
    '************************************************************************* Gg8F>y<[R  
    eID = FindMaterial( "Lens" ) b
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    GetModelMaterial eID, mat "K;f[&xO,o  
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    mat.Nd = nlens 7\HjQ7__  
    SetModelMaterial eID, mat \$$DM"+:;H  
    Print "Set lens index of refraction = " & nlens <>%2HRn<u  
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    '************************************************************************* !E#FzY!}Pl  
    'Pupil diameter @vs+)aRa  
    '************************************************************************* c>mTd{Abi  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) M8(N9)N  
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    'Adjust pupil diameter (trimming volume inner hole) 9bwG3jn4?  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" EIug)S~  
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    ' Adjust pupil location to just in front of the lens $MhfGMk!'  
    parID = FindFullName( "Geometry.Arizona Eye" ) N3"O
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]O]6O%.ao  
    count = 0 Nz1u:D]  
    While GetOperationCount(eID)>count LYhjI  
        GetOperation eID, count, op ~+ [T{{  
        If op.Type="ShiftZ" Then [&eG>zF"  
            DeleteOperation eID,count /fgy07T  
            count=count-1 yI$KBx/]n  
        End If @^R6}qJ  
        count=count+1 /#TtAkH  
    Wend E&G]R!  
    op.Type = "ShiftZ" "!,)Pv  
    op.val1 = taq-0.01 #l 7(WG  
    op.parent = parID
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    AddOperation eID, op mH6\8I  
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    Print "Set pupil diameter = " & pupilDiam 8GlRO4yd  
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    'Update AZ Eye subassembly Description q!f'?yFYK  
    eID = FindFullName( "Geometry.Arizona Eye" ) [$]qJ~kz  
    GetEntity eID, entity B5v5D[ o5  
    entity.Description = "Accommodation = " & A & "D" tw k  
    SetEntity eID, entity \&BT#8ELG  
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    Update 5LaF'>1yY  
    Print "DONE!" [jnA?Ge:  
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End Sub C:r3z50  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： <]Btx;}  
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Accommodation = 4 Diopters dC>[[_  
Pupil Diameter = 4 mm /`s{!t#Y  
Set aqueous humor thickness = 2.81 =[do([A  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Kt3T~k  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 #u"$\[G  
Set lens thickness = 3.927 ,Jrm85oG  
Set lens index of refraction = 1.42672 xcE2hK/+  
Set pupil diameter = 4 |Ml~_m  
DONE! T3bYj|rh=